package homework;

import java.util.Locale;
import java.util.Scanner;

public class Test4 {

    //
    public static void PD(String str){

       char[] ch=str.toCharArray();
       int [] arr=new int[26];
       for(int i=0;i<ch.length;i++){
           if(ch[i]>='A'&&ch[i]<='Z'){
               int a=ch[i]-'A';
               if (arr[a] == 0){
                   System.out.print(ch[i]);
                   arr[a]++;
               }
           }
           else if (ch[i]>='a'&&ch[i]<='z'){
               int a=ch[i]-'a';
               if (arr[a] == 0){
                   System.out.print(ch[i]);
                   arr[a]++;
               }
           }

       }
    }
    public static void main(String[] args) {

       String str;
        Scanner in=new Scanner(System.in);
        while(in.hasNext()){
            str=in.nextLine();
            PD(str);
        }


    }
}
